No it doesn't actually start the drive wave. Just little blips instead. Like it's trying to start
I don't understand what you meant by:
I put new 21844s chips it and it starts up every time now.
Please explain.
I put new 21844s chips it and it starts up every time now.
Please explain.
I noticed the the input signal to the pin 1 of the chips isn't good. Very sporadic. Not a clean wave thru time. Jumping all over the place
Where is your scope grounded on the amp?
In this amp, is the negative speaker terminal directly connected (0 ohms) to the secondary center-tap?
Are the RCA input shields directly connected to the negative speaker terminal?
In this amp, is the negative speaker terminal directly connected (0 ohms) to the secondary center-tap?
Are the RCA input shields directly connected to the negative speaker terminal?
It's grounded thru the mains but I also have a handheld scope.
Yes the speaker neg. Is directly connected to the 2ndary ground.
Yes the rca shields are also directly connected to the speaker neg.
Yes the speaker neg. Is directly connected to the 2ndary ground.
Yes the rca shields are also directly connected to the speaker neg.
Ground the scope to the negative speaker terminal. Do you still get the same pulsing that you've seen before.
You could also go to differential mode for the mains-powered scope.
I don't know the quality of the handheld scope so I don't know if it will be of any use.
You could also go to differential mode for the mains-powered scope.
I don't know the quality of the handheld scope so I don't know if it will be of any use.
It's older but it was an expensive unit back in the day.
I have 2 different audio cards I can swap between. When I put one in I get no switching attempt but the rail voltage builds smooth. The other card looks like it's trying but the rail voltage doesn't build smoothly. It jumps around. Both cards have new 21844s chip in them
I have 2 different audio cards I can swap between. When I put one in I get no switching attempt but the rail voltage builds smooth. The other card looks like it's trying but the rail voltage doesn't build smoothly. It jumps around. Both cards have new 21844s chip in them
Does the voltage on the SD pin remain within a volt of the negative rail voltage until the rail voltage builds completely?
Pin 1 is the input and I wouldn't expect to see 1.2k there. Either it's before normal oscillation and it's whatever you're driving into it or it's the self-oscillating frequency which should be near 100kHz.
The amplitude also seems low.
Is the output of the LM211 swinging fully ±5v?
What's the amplitude of the signal on the MPSA92 end of the 820 ohm resistor?
Is your scope calibrated? If you're not sure, post a photo of the PS drain waveform and the DC voltage you read across the B+ and ground (read with a multimeter).
The amplitude also seems low.
Is the output of the LM211 swinging fully ±5v?
What's the amplitude of the signal on the MPSA92 end of the 820 ohm resistor?
Is your scope calibrated? If you're not sure, post a photo of the PS drain waveform and the DC voltage you read across the B+ and ground (read with a multimeter).
Sorry I should have told u I'm powering it up with +/- 20v to keep the rails lower than the +/-180v they're normally at.
That is the self oscillation frequency
What mpsa92?
The lm211 only goes up to 2.6v
That is the self oscillation frequency
What mpsa92?
The lm211 only goes up to 2.6v
Does the LM211 have ±5v on its power supply terminals?
OK, MMBTA92. It will be marked 2D and will come after the 820 ohm resistor that is fed by the EF pair off of the LM211. The MMBTA92 shifts the drive from a ground reference to a -rail reference.
Don't the regulated voltages come from dedicated windings and are therefore unaffected by the low rails?
OK, MMBTA92. It will be marked 2D and will come after the 820 ohm resistor that is fed by the EF pair off of the LM211. The MMBTA92 shifts the drive from a ground reference to a -rail reference.
Don't the regulated voltages come from dedicated windings and are therefore unaffected by the low rails?
Yes the 211 has +/- 5v
I am using a old low power class a/b amp for the voltages I need
I'm not finding an 820k resistor. Here's a pic of the driver card
I am using a old low power class a/b amp for the voltages I need
I'm not finding an 820k resistor. Here's a pic of the driver card
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Why isn't the LM211 swinging fully to the supply voltages?
Are you sure that it's not a calibration problem with your scope that's making it appear to be swinging less than ±5v?
Are you sure that it's not a calibration problem with your scope that's making it appear to be swinging less than ±5v?
